This disclosure relates to multi-segment air bag tether systems and to a pattern-wise arrangement of such tether segments in relation to air bag panels on a fabric blank, thus resulting in increased fabric utilization and an overall cost savings per finished air bag. The air bag tether system as described herein is comprised of two multi-segment congruent tether groups that are joined to one another and to a respective air bag panel. The segments that comprise each tether group are cut substantially on the bias with respect to the warp or the fill of the fabric blank. This multi-segment construction decreases the amount of fabric that is used in the manufacture of the air bag and tether systems, while providing sufficient elongation for the tether system to be functional.
Because of the speed with which an air bag inflates, it is necessary for the protection of vehicle occupants to control the volume of space that the air bag occupies in the vehicle cabin. Traditionally, air bag tethers have been used to control the excursion of an air bag as it inflates. As gas is released, causing the air bag to rapidly inflate, it is necessary to keep such inflation from occurring in an uncontrolled manner. Tethers, which are sewn to the interior portions of the front and rear panels of an air bag, keep the inflating air bag from expanding so rapidly as to adversely affect the safety of the vehicle occupant, as the vehicle occupant contacts the air bag.
Tethers are conventionally strip-shaped pieces of fabric that are aligned in pattern-wise arrangement on a fabric blank, or that are aligned in relation to air bag panels that may be cut from the same blank. These tethers typically include a circular portion in the center area of the tether strip used for attachment of the tether strip to the air bag panel. It is understood in the industry that such tethers should have a capacity for elongation (that is, the tethers should be able to stretch to accommodate the rapid excursion of the bag). For this reason, conventional strip-shaped tethers have historically been cut on the bias with respect to the warp and fill of the fabric. However, utilizing these one-piece tethers increases the amount of fabric needed to create an appropriate number of tethers for a plurality of air bags, thus resulting in increased production costs.
The present air bag tether system, with groups of tether segments attached to each bag panel, addresses the problems of fabric utilization and tether elongation. Using a multi-segment tether system in place of conventional one-piece tethers improves fabric utilization by allowing these bias-cut tether segments to be arranged around air bag panels into spaces that might otherwise be considered fabric waste. The segments that comprise the tether groups are each cut substantially on a bias with respect to the warp and fill of the fabric blank. This multi-segment approach, rather than one-piece tethers, leads to an improved fabric utilization, while providing a tether system that is capable of sustaining the forces exerted by the inflating air bag.